Three-dimensional image reconstruction using multi-layer data acquisition

Abstract

A camera, including: two imaging systems each comprising a different optical path corresponding to a different viewing angle of an object; one or more illumination sources; a mask disposed with multiple pairs of apertures, wherein each aperture of each aperture pair corresponds to a different one of the imaging systems; at least one detector configured to acquire multiple image pairs of the object from the two imaging systems via the multiple pairs of apertures; and a processor configured to produce from the multiple acquired image pairs a multi-layer three dimensional reconstruction of the object.

The invention claimed is: 
     
       1. A system, comprising:
 A. a camera configured to operate under telecentric conditions, said camera comprises:
 two imaging systems each comprising a different optical path corresponding to a different viewing angle of an object; 
 one or more illumination sources, comprising at least one illumination source having a wavelength that is beyond the visible spectrum; 
 a mask comprising multiple pairs of apertures, wherein each aperture of each aperture pair corresponds to a different one of the imaging systems, wherein each aperture of each of said pairs of apertures is configured to transmit a light pulse from a different optical path to at least one imaging sensor, wherein said multiple pairs of apertures are positioned symmetrically opposite about the viewing axis of said camera; and 
 at least one detector configured to acquire multiple image pairs of the object from the two imaging systems via the multiple pairs of apertures; and 
 
 B. a processor configured to produce, from the multiple acquired image pairs, a multi-layer three-dimensional reconstruction of the object,
 wherein said viewing angle is between 3 and 9 degrees. 
 
 
     
     
       2. The system of  claim 1 , wherein each pair of apertures is dedicated to a different illumination source of the one or more illumination sources. 
     
     
       3. The system according to  claim 1 , wherein the one or more illumination sources comprise a first illumination source of a first wavelength, a second illumination source of a second wavelength, and a third illumination source of a third wavelength. 
     
     
       4. The system of  claim 3 , wherein each of the one or more illumination sources has a full-width-at-half (FWHM) bandwidth of 10 nm±10%. 
     
     
       5. The system according to  claim 1 , wherein the one or more illumination sources comprises multiple illumination sources, and wherein the at least one detector comprises a mono sensor having a dedicated region for each aperture, and configured to simultaneously capture multiple images comprising an image for each of the multiple illumination sources and for each of the imaging systems. 
     
     
       6. The system according to  claim 1 , wherein the at least one detector comprises two imaging sensors that are each dedicated to one of the imaging systems and are configured to simultaneously detect an image pair for each of the illumination sources. 
     
     
       7. The system according to  claim 1 , wherein the one or more illumination sources comprises multiple illumination sources, and wherein the at least one detector comprises an imaging sensor having multiple sensor regions, each sensor region dedicated to a different one of the multiple apertures, and wherein the multiple sensor regions are configured to simultaneously capture multiple images comprising an image for each of the multiple illumination sources and for each of the imaging systems. 
     
     
       8. The system according to  claim 1 , wherein at least one of the one or more illumination sources is disposed with a polarization component, and wherein at least one of the apertures dedicated to the illumination source disposed with the polarization component, is disposed with a complementary polarization component. 
     
     
       9. The system of  claim 8 , wherein the at least one of the apertures disposed with the polarization component is dedicated to a blue light source. 
     
     
       10. The system according to  claim 1 , wherein each pair of apertures is disposed with a color filter corresponding to its dedicated illumination source. 
     
     
       11. The system according to  claim 1 , further comprising at least one back lens configured to focus light transmitted via the multiple pairs of apertures of the mask to the at least one detector. 
     
     
       12. The system according to  claim 1 , wherein at least one image pair of the acquired image pairs corresponds to a specular reflection off the object, and wherein the processor is further configured to use the at least one image pair to measure a depth characteristic of the object. 
     
     
       13. The system of  claim 12 , wherein the processor is further configured to apply a shift to the pixels of the acquired image as a function of the depth characteristic. 
     
     
       14. The system according to  claim 1 , wherein at least one of the acquired images corresponds to a diffuse reflection off the object, and wherein the processor is further configured to use the at least one acquired image to measure a hemoglobin level of the object. 
     
     
       15. The system according to  claim 1 , wherein at least one of the acquired images corresponds to a diffuse reflection off the object, and wherein the processor is further configured to use the at least acquired one image to measure a melanin level of the object. 
     
     
       16. The system according to  claim 1 , wherein the processor is configured to use at least one of the acquired images to measure a color characteristic of the object. 
     
     
       17. The system according to  claim 1 , wherein the processor is configured to synchronize the illumination source with a shutter of the camera. 
     
     
       18. The system according to  claim 1 , further comprising a user interface configured to display the multi-layer three-dimensional reconstruction of the object. 
     
     
       19. The system according to  claim 1 , wherein said processor is configured to produce a three-dimensional (3D) point cloud representing the object, based, at least in part, on said multiple image pairs of the object. 
     
     
       20. The system according to  claim 19 , wherein said multiple image pairs of the object are a series of consecutive image pairs each representing a region of said object, wherein said processor is configured to produce a 3D point from each image pair of the series of consecutive image pairs, and wherein said processor is further configured to add all the 3D point clouds together into a single 3D point cloud representing said object. 
     
     
       21. The system according to  claim 3 , wherein said one or more illumination sources comprise a combination of one or more illumination sources having a wavelength that is beyond the visible spectrum, and one or more illumination sources having a wavelength that is in the visible spectrum. 
     
     
       22. A method comprising:
 controlling an illumination cycle comprising a blue illumination pulse by a blue light source, a green illumination pulse by a green light source, and a red illumination pulse by a red light source; 
 synchronizing a camera shutter with each illumination pulse of the illumination cycle; 
 acquiring a pair of images of an object during each illumination pulse; 
 calculating a depth characteristic of the object using one of the pairs of images acquired from a specular reflection of one of illumination pulses; 
 applying a shift to the pixels of the acquired image as a function of the depth characteristic; 
 measuring a sub-surface quality of the object using any of images acquired from a diffuse reflection of any of the illumination pulses; 
 determining a color characteristic of the object from any of the acquired images; 
 registering the pairs of images received over multiple illumination cycles; and 
 combining the registered pairs of images to create a multi-layer three-dimensional reconstruction of the object.